Adoption is the legal act of severing the parental responsibilities and rights of the biological parents of a child and placing those responsibilities and rights onto adoptive parents, taking a child who is not a blood relative into one's own family. Also the biological parents may have lost their responsibilities and rights earlier, or have died (a minority of children who are adopted have been orphaned). It also affects inheritance, for which adopted children are treated as own children.

A related case where government intervention has resulted in adoption is the case where the child's blood relatives belong to an outgroup culture which has been deemed unfit as a whole by the controlling government. Aboriginal Peoples in Australia were affected by such policies, as were Native Americans in the United States and Canada.

Different jurisdictions have varying laws on adoption and post-adoption. Some practise closed adoption, preventing further contact between the adopted person and his/her natural parents, while others have varying degrees of open adoption, which may allow such contact.

Many adopted people and natural parents who were separated by adoption have a natural desire to reunite. In countries which practise closed, secret adoption, this has led to efforts to circumvent sealed records (for example, see Adoption Reunion Registries) and efforts to establish the right of adoptees to access their sealed records (for example, see Bastard Nation).

Adoption is also presented as an argued alternative to abortion.

See also: Affiliation - Adoption in Rome - Bastard Nation